Although weapons such as firearms can provide a great deal of protection in a hostile situation, a loaded gun is a dangerous instrumentality which may be used against a law-enforcement officer by a criminal perpetrator. Accordingly, numerous inventions have been devised and protected relating to firearm safety, with one goal being the prevention of misuse. In particular, a variety of mechanisms exist which prevent the firearm from discharging either accidently, such as upon impact with a hard surface, or intentionally by an unauthorized user, such as a child or criminal. Such safety mechanisms are variously configured, and include mechanical and magnetically operated key-type mechanisms as well as mechanisms electronically operated.
Such safety mechanisms typically prevent the firing of a weapon by either disabling a linkage that acts upon the firing-pin, or by disabling the firing-pin directly. For example, U.S. Pat. No. 5,016,376 to Pugh discloses a magnetically actuated firearm locking mechanism wherein a solenoid, actuated or deactuated upon receiving an electrical signal, moves a locking rod into a position which prevents the firing of the weapon by blocking the movement of the hammer or trigger. The solenoid is in electrical communication with a decoder. A user must possess an encoder which creates a signal received by the decoder indicating that the user is authorized to use the weapon. The decoder then actuates the solenoid to move the locking rod linkage into a position whereby the firearm may be operated.
Other safety mechanisms for firearms operate by directly blocking movement of the firing-pin. U.S. Pat. No. 4,090,316 to Volkmar discloses a firearm which has a firing-pin pivotable between safety and firing positions by a release lever. The hammer of such firearm has a striking surface which engages the firing-pin only when the firing-pin is in its firing position. When the firing-pin is in a safety position, the striking surface of the hammer does not engage the firing-pin, thus preventing discharge of the firearm.
Likewise, U.S. Pat. No. 4,658,529 to Bertolini discloses a firearm safety mechanism which acts directly on the firing-pin. The firing-pin is provided with an annular groove which interacts with a rib disposed on a safety latch, the safety latch being moveable between an "on" and "off" position. As the safety is moved into the "on" position, the rib enters the annular groove on the firing-pin, camming the firing-pin so as to retract and lock the pin into a fixed position. When the safety is moved to the "off" position, the rib disengages the firing-pin, positioning the firing-pin so that the hammer end of the firing-pin may be impacted by the hammer.
Although the prior art discloses electronically activated safety mechanisms in general, and mechanical latch mechanisms in particular, all existing devices either operate on mechanisms removed from the firing-pin, and are therefore more prone to malfunction, or, if they act directly on the firing-pin, are too complex or unreliable, thereby requiring frequent maintenance.